In the manufacture of glass and glass fibers, glass batch is melted in large furnaces which release gases which in the past have been released to the atmosphere. With the growing concern over the environment and pollution, these gases are now treated with wet scrubbers, a dry scrubber and other like equipment to remove harmful constituents in the gases before their release to the atmosphere. In one such treatment, acidic gases from a furnace stack are treated with a spray of alkaline material to neutralize the acidic materials contained in the gases and to condense some of the constituents of the stream in the treatment zone. One problem encountered with such a system is the problem of corrosion of the spray nozzles used to release the spray of alkaline material used to treat the gases. The problem is caused by the continuing contact of the highly acidic constituents of the gases present in the stream being treated with the metal surfaces of the spray nozzles. The corrosion attendant such a constant contact of acids with metal requires frequent replacement of the spray nozzles employed and the consequent shut down of the gas-liquid contact system for such replacement.
In U.S. Pat. No. 2,712,961 a spraying apparatus for treating a gaseous stream is disclosed. In this patent, the spray nozzle is protected from the environment surrounding it by forcing a stream of hot steam over the spray nozzle from an opening positioned well above the nozzle.
It is desirable to protect the spray nozzle from the harmful gases present in the system, thus reducing corrosion and its associated problems, without the necessity of employing a heated stream to protect the nozzle. It is also desirable to minimize exposure of pipes carrying the spray liquids or the protecting material to the gases present in the system.